English verb conjugation
COULD PERTAIN

Regular verb: pertain - pertained - pertained

Affirmation

Simple form	V-ing form
I could pertain you could pertain she could pertain we could pertain you could pertain they could pertain	I could be pertaining you could be pertaining she could be pertaining we could be pertaining you could be pertaining they could be pertaining
Perfect	V-ing perfect
I could have pertained you could have pertained she could have pertained we could have pertained you could have pertained they could have pertained	I could have been pertaining you could have been pertaining she could have been pertaining we could have been pertaining you could have been pertaining they could have been pertaining

Negation

Simple form	V-ing form
I couldn't pertain you couldn't pertain she couldn't pertain we couldn't pertain you couldn't pertain they couldn't pertain	I couldn't be pertaining you couldn't be pertaining she couldn't be pertaining we couldn't be pertaining you couldn't be pertaining they couldn't be pertaining
Perfect	V-ing perfect
I couldn't have pertained you couldn't have pertained she couldn't have pertained we couldn't have pertained you couldn't have pertained they couldn't have pertained	I couldn't have been pertaining you couldn't have been pertaining she couldn't have been pertaining we couldn't have been pertaining you couldn't have been pertaining they couldn't have been pertaining

Interrogative form

Simple form	V-ing form
could I pertain? could you pertain? could she pertain? could we pertain? could you pertain? could they pertain?	could I be pertaining? could you be pertaining? could she be pertaining? could we be pertaining? could you be pertaining? could they be pertaining?
Perfect	V-ing perfect
could I have pertained? could you have pertained? could she have pertained? could we have pertained? could you have pertained? could they have pertained?	could I have been pertaining? could you have been pertaining? could she have been pertaining? could we have been pertaining? could you have been pertaining? could they have been pertaining?

Interro-negative form

Simple form	V-ing form
couldn't I pertain? couldn't you pertain? couldn't she pertain? couldn't we pertain? couldn't you pertain? couldn't they pertain?	couldn't I be pertaining? couldn't you be pertaining? couldn't she be pertaining? couldn't we be pertaining? couldn't you be pertaining? couldn't they be pertaining?
Perfect	V-ing perfect
couldn't I have pertained? couldn't you have pertained? couldn't she have pertained? couldn't we have pertained? couldn't you have pertained? couldn't they have pertained?	couldn't I have been pertaining? couldn't you have been pertaining? couldn't she have been pertaining? couldn't we have been pertaining? couldn't you have been pertaining? couldn't they have been pertaining?